This invention relates to stacking apparatus for singularly receiving a stream of articles and causing the articles to be placed in a stack.
It is known, for example, in mail processing systems to use a drop power stacker for receiving envelopes ejected from a mailing machine. A conventional drop power stacker is generally a fixed length apparatus and includes a receiving deck mounted throughout to a base. Conventionally the power stacker is supportably placed on a table abutting at one end to a mailing machine.
In one such conventional power stacker, envelopes ejected from the mailing machine are drop fed onto the deck of the power stacker. The power stacker includes one or more endless belts for advancing the envelopes along the stacker deck. The endless belts are driven at a rate of speed chosen to cause the received envelopes to assume a shingled alignment along the stacker deck. A rotatively driven wheel is mounted to the power stacker to engage a portion of the upper envelopes' surface to assist in providing the proper shingling drive force to the envelopes. As the envelopes encounter the power stacker end wall, shingle space compression accrues causing the envelopes to assume a fan orientation characterized by fan or shingle angle. As a result the capacity of the power stacker in addition to its length its maximum shingle angle.